Jerry - it looked like the Corvette manifold to me also.
You are probably right that the initial cost of the SU's would be less. I doubt seriously that the final cost would be less. 90 percent of the SU's we worked on 40 years ago needed major machine work. I cannot believe they have magically repaired themselves. And that is just to get them so they would work, NOT recalibrate for the Chevrolet engine!
If I had that manifold, I would be looking for some of the marine YH Carters. While the calibration depended on the application, all of the YH's were designed for lower RPM engines, so the calibrations would be at least acceptable.
The major difference from the Corvette YH's to all other YH's was the Corvette used manual chokes. All others used auto chokes.
The manual choke on the YH was one of the poorer of all Carter ideas. The manual pull cable was attached to a zinc alloy (pot metal housing), and the housing was similar to voting in Chicago (vote early, vote often is replaced by break early, break often)!
The manual choke housing today (never used on any other Carter carb) is worth almost as much as the entire carburetor! Someone once machined them from brass, but even though they were much more reliable, they didn't sell because they could not be chromated. Very few drive the 6 cylinder Corvettes, they just look at them, and every little thing has to look correct.
We have helped several enthusiasts make the marine YH's work on the 235 with the Corvette intake.
And it is said a picture is worth a 1000 words:
Comparison new old stock Corvette carb & Nash carb:
http://www.thecarburetorshop.com/YH_manual_and_auto.jpgNew old stock Corvette carb:
http://www.thecarburetorshop.com/YH_manual.jpgMechanical rebuild of Nash carb:
http://www.thecarburetorshop.com/YH_auto.jpgJon.
